Spacecraft are typically constrained in their dimensions by the volume available within the fairing of the launch rocket. This has led to the development of various types of deployable structure which can be stowed into a relatively small volume for launch, and later deployed to increase the dimensions of the spacecraft. For example, large components such as solar panels can be mounted on hinged booms which allow the panels to be folded alongside a satellite body during launch, and then unfolded once the satellite is in orbit to provide a much larger surface area. Such deployable structures may use motor-driven cables or hinges to control the unfolding of the structure, or alternatively may use sprung hinges which store elastic energy when folded and allow the structure to deploy under its own force, once a tie-down device is released. An example of such a self-deploying boom structure is disclosed in U.S. Pat. No. 6,343,442 B1.
Additionally, many applications may require use of a closed structure rather than a simply linear or planar structure. For example, it may be desired to provide a telescope shroud which is several metres in diameter and tens of metres in length, and has an internal cross-section which provides an unobstructed path for light beams, i.e. free from supporting booms/masts. Alternatively, a tube-like structure may be required for a sunshield or baffle, or may simply be desirable for the increased rigidity offered by a tubular or polygonal cross-section. Particularly in the case of a telescope body, which both shields the internal components and provides structural support, it is necessary for the deployed structure to have precisely controlled dimensions. Prior art solutions for tube-like deployable structures include telescoping structures which require complex and cumbersome mechanisms, and inflatable structures which are stiffened by chemical cross-linking in space but offer poor control over final dimensions.